1. Field of the Invention
Embodiments of the invention generally relate to a pulsing tool for reducing frictional forces encountered by a conveyance string during operation.
2. Description of the Related Art
One of the difficulties coiled tubing “CT” operations encounter is the inability to reach total depth due to high drag forces. The nature of coiled tubing is such that the drill string is not capable of being rotated, so a rotating friction reduction tool is not a viable option. Another limiting factor is that the operations are generally run in very tight or small diameter holes. In some cases, CT operations are performed to refurbish existing wells where mineral buildup and other factors have hindered the flow of oil or gas. The average diameter for a CT is only 2⅞ inches, whereas a standard operation using jointed drill pipe may run pipe ranging from 4 inches to 8 inches, in holes of up to 36 inches in diameter. Additionally, if the wellbore has horizontal sections, high frictional drag forces may be generated when the CT is lying on the bottom side of the wellbore.
There is a need, therefore, for apparatus and methods to reduce the frictional forces encountered by the conveyance string during operation.